The course covers the techniques a thin film scientist reaches for most often, but the full landscape is far larger. This appendix serves two purposes: it is the suggested topic list for the final project, and it is a map of what else exists, organized by the question each technique answers. Techniques marked with an asterisk are popular final project choices; anything on this page is fair game, as is any technique not listed here, proposed with a sentence of justification.
Electronic structure¶
ARPES* (angle-resolved photoemission): the band structure E(k) of a surface or 2D film, measured directly. The defining spectroscopy of quantum materials.
UPS: valence bands and work function in the laboratory.
Inverse photoemission / two-photon photoemission: the unoccupied states.
Cathodoluminescence*: light emission under the electron beam, mapping band gaps and defects at SEM/STEM resolution.
Atomic structure and diffraction¶
Surface X-ray diffraction: full surface crystallography at synchrotrons, including buried interfaces no electron can reach.
X-ray absorption spectroscopy (EXAFS/XANES)*: local coordination and oxidation state, element by element, crystalline or not.
Pair distribution function analysis*: total-scattering structure of amorphous and nanocrystalline films.
Low-energy electron microscopy (LEEM/PEEM)*: real-time full-field imaging of surface dynamics, growth, and phase transitions at nanometer resolution.
Field ion microscopy: the ancestor of atom probe; atomic imaging of tips.
Neutron diffraction and reflectometry*: isotopic and magnetic contrast in depth profiles.
Composition and chemistry¶
Nuclear reaction analysis (NRA): isotope-specific depth profiling, the standard for hydrogen via the 15N method.
Particle-induced X-ray emission (PIXE): trace element mapping with MeV protons.
X-ray fluorescence (XRF/TXRF)*: fast, standards-capable composition and areal density; TXRF monitors wafer contamination at 10^10 atoms/cm2.
Glow discharge spectroscopies (GD-OES/GDMS)*: rapid depth profiling through many micrometers, coatings-industry standard.
Electron probe microanalysis (EPMA/WDS), colloquially the microprobe: the quantitative standard for micron-scale composition.
Raman variants (TERS, SERS)*: near-field and plasmon-enhanced chemical mapping down to nanometer scales.
Sum-frequency generation spectroscopy*: vibrational spectroscopy that is interface-selective by symmetry, for buried and liquid interfaces.
Adsorption, kinetics, and surface energetics¶
Temperature-programmed desorption (TPD)*: binding energies and coverages of adsorbates, the workhorse of surface chemistry and catalysis.
Quartz crystal microbalance (QCM)*: sub-monolayer mass sensing, in vacuum or liquid.
Contact angle and adsorption isotherm methods: surface energy and porosity of films.
Morphology, mechanics, and properties¶
Optical profilometry and interferometry*: fast areal topography over millimeters, complementing AFM’s small field.
Nanoindentation*: hardness and modulus of films, with the substrate-effect corrections that make thin film indentation its own discipline.
Wafer curvature (Stoney) stress measurement*: in situ film stress during growth.
He ion microscopy*: sub-nanometer imaging of uncoated insulators, plus nanofabrication.
Electron holography*: quantitative electrostatic and magnetic field mapping in the TEM.
4D-STEM methods (ptychography, orientation and strain mapping)*: computational diffraction imaging beyond what we cover in Module 6.
Scanning SQUID and NV-center magnetometry*: quantitative nanoscale magnetic field imaging.
In situ and operando TEM*: films observed during heating, biasing, and electrochemistry.
Cryo-EM and cryo-FIB for materials*: beam-sensitive and hydrated films, methods imported from structural biology.
Historical reference¶
The full 1980s-era table of surface science acronyms from earlier versions of this course, more than a hundred entries from ADAM to XRD, is preserved in the course archive. Most modern techniques are recombinations of the same probes and signals, and most of the combinations were named early. What has changed is which combinations proved to matter.